This invention relates an instant type camera having means for preventing the movement of an exposed film unit from an imbibition chamber into the ambient light until its image has been sufficiently developed.
Cameras of the instant type having an imbibition chamber into which an exposed film unit may be moved and stored until its latent image has been sufficiently developed to permit its movement into the ambient light are generally well known. For example, reference may be had to U.S. Pat. Nos. 3,426,664 and 3,537,370 wherein film units of the instant type are sequentially exposed and moved to a lighttight chamber in which a previously applied layer of a liquid is allowed to imbibe layers of the film unit for a time sufficient to produce a visible image in the film unit. Each of the storage chambers includes a door which may be opened to permit removal of the exposed film unit. However, no provision is made for viewing the image in the film unit without opening the door to the storage chamber. Further, no means are provided for preventing premature opening of the door, i.e., opening the door before the developing image has reached the state wherein it is no longer susceptible to being further exposed by ambient light.
U.S. Pat. No. 2,794,377 shows an instant type camera having an imbibition chamber in which a film unit is maintained in a light free environment until its image has been developed. The chamber includes a door which may be opened for removal of a positive sheet of the film unit, only after the emerging image in the film unit is no longer susceptible to being adversely affected by the ambient light. Again, no provision is made to view the image in the film unit located in the chamber without opening the door; nor can a plurality of film units be stored within the imbibition chamber.
U.S. Pat. No. 4,664,497 shows an instant type camera which addresses and solves most of the problems enumerated above. Specifically, the patent shows an instant tpye camera having an imbibition chamber for retaining one or more exposed film units in a light free environment during development of a latent image, a window through which the developed image may be viewed, and means for removing the film units from the imbibition chamber. However, it is possible for the user of this camera to manually actuate the means for removing a film unit from the imbibition chamber before its developing or emerging image is ready to be exposed to the ambient light.